/Engine/Source/Runtime/Engine/Public/SparseVolumeTexture/SparseVolumeTextureData.h
Holds the data for a SparseVolumeTexture that is stored on disk. It only has a single mip after importing a source asset. The mip chain is built during cooking. Tiles are addressed by a flat index; unlike the runtime representation, this one stores all tiles in a 1D array (per mip level) and doesn't have the concept of a 3D physical tile texture. The page table itself is 3D though.
struct FTextureData
TStaticArray< F...
FallbackValuesQuantized
FHeader
Header
TArray<FMipMap...
MipMaps